One of the best ways to understand how great or awful a car is, is to tear it apart, piece by piece, and examine how it was designed and assembled.

If you take apart a Tesla Model 3, as engineering experts Munro & Associates have done, you come away with an appreciation of why Tesla scares the pants off every other automaker. But you also understand why Silicon Valley's automotive newbie is struggling to produce cars profitably.

Where Tesla excels is in the Model 3's skateboard-like, lithium-ion battery pack and related power electronics. "We are shocked by the advanced integration and advanced manufacturing techniques" used in the electronic control center, Chief Executive Sandy Munro told members of the Automotive Press Association on Wednesday. "This is the brilliance of the Tesla Model 3."

Yet Munro was dumbfounded by other aspects of the vehicle, particularly the mostly steel skeleton, known as a body-in-white, which was sloppily joined together using a potpourri of robotic welding techniques, helping to explain the Model 3's ill-fitting body panels. "If the fixture is wrong, the fit-and-finish is bad," said Munro. Poor fit-and-finish -- like uneven gaps between panels or improper alignment of parts -- is not just unsightly. It's often the cause of annoying squeaks and rattles or more serious quality problems.

The fact that Tesla can simultaneously demonstrate brilliance and incompetence in the same vehicle is not surprising, considering it is a high-tech software company trying to master complex manufacturing processes that took established automakers more than 100 years to perfect.

Munro, whose Auburn Hills, Mich.-based consulting firm makes money selling its benchmarking studies to automakers, says his analysis is not complete so it's too early to draw any conclusions about how the Model 3 stacks up to other electric cars it has studied like the BMW i3 or Chevrolet Bolt EV. "Everything that's below the floor pan is amazing. Everything above it is what it is," he said. But the "dinosaur" stuff, like basic manufacturing techniques, can be fixed with the proper resources and investment, he added.

Munro purchased the Model 3 in early December for $72,000 from another buyer but he had no information about when the car was manufactured. The car was never driven prior to Munro taking possession in late January, but "it was held back by Tesla for two extra weeks due to an undisclosed quality issue." The firm has since purchased a second Model 3, Munro said. "It's better, but not much better."

A Tesla spokesperson said the primary car evaluated by Munro was built in 2017, adding: "We have significantly refined our production processes since then, and while there’s always room for improvement, our data already shows that Model 3 quality is rapidly getting better.”

For example, Tesla said the standard deviation of Model 3 gaps has improved by nearly 40 percent, with especially visible improvements in the area of the trunk, rear lamps and rear quarter panel. "Today, Model 3 panel gaps are competitive with Audi, BMW, and Mercedes models, but in the spirit of relentless improvement, we are working to make them even tighter.”

Tesla Chief Executive Elon Musk boasts that the Model 3 was designed for easy assembly, using fewer parts, and Munro's team found several examples of this. The accelerator pedal, for example, snaps into its housing using a tab and slot, then locks in place with a single screw, where traditionally there would be at least three fasteners. The aluminum cross-car beam, which supports the dashboard, has plastic parts that are "over-molded" through injection molding rather than attached using traditional fasteners.

There are other components that appear to the untrained eye to be jerry-rigged, leaving even Munro experts guessing about their purpose. A damper weight on a suspension control arm, for example, was secured using glue and industrial-strength zip ties. That said, the engineers said the Model 3 had "phenomenal" handling before they tore it apart, suggesting Tesla got the car's suspension just right.

Most confounding to Munro and his team was the body construction of the Model 3. "This car is the heaviest body-in-white I've ever seen," he said, calling the construction "ridiculous" and highlighting areas where Tesla needlessly added weight with things like excess metal flanges and overlapping layers of steel. "This adds weight without value," he said.

He was also puzzled by Tesla's unconventional use of multiple welding techniques in close proximity to one another. "I don't get it," he said. "There's a lot of technology [used] here, but what we don't understand is why they used the technology they did."

Other signs of waste: the wheel wells are constructed of 9 different pieces of metal instead of one, as in most vehicles. And because they are symmetrically opposed to the wheel wells on the opposite side of the car, extra tooling is required, which drives up costs.

A Tesla spokesperson acknowledged room for improvement on the car's mass and complexity but said the Model 3 was designed for safety, noting that electric cars have unique safety requirements to prevent intrusion into the battery.

There's no doubt Tesla rivals will be poring over Munro's $87,000 benchmarking study of this early production vehicle when it is completed in a couple of months. But with Musk vowing to work his way out of production hell to finally achieve a steady production rate of 5,000 vehicles per week by the end of June, Munro would be wise to buy another car and start working on a sequel.

I'm the Detroit bureau chief for Forbes, which means I spend most of my time covering the automotive industry. But I also keep an eye on the rest of America's heartland—where stuff is manufactured and grown. I've been on the auto beat for more than 20 years at Forbes, Busin...